In order to realize power saving, a printer shifts from a power supply mode to a power saving mode in which power supply to some components is reduced relative to the power supply mode and thus power consumption is suppressed.
A background printer has a power saving mode. The printer is configured to display a message indicating that shifting to a low power consumption mode is not possible when a user inputs shift instructions for shifting from a power supply mode to a low power consumption mode, during an operation of the printer having the low power consumption mode (corresponding to the power saving mode). In the power saving mode, power consumption in a standby state is suppressed.